Maximum subarray using cumulative array

#1

Why is the value of right and left initialized with the value of -1 ?
Is it compulsory to have -1 or can we begin those variables with 0 also?

#2

Also please explain, in maximum subarray using cumulative array,
currsum=cumsum[j]-cumsum[i-1];

since the value of i has been initialized from 0, therefore on putting i=0, we get currsum=cumsum[0]-cumsum[-1]
so I don’t know how can we find the value of cumsum[-1] ?
…

#3

Yes you should prevent negative indexes in the array as it may have some unexpected results depending on the compiler. But here it is not causing any error and taking cum[-1] as 0. It basically depends on the compiler.

#4

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